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Clinical evaluation of the MPS 9000 Macular Pigment Screener
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  • Published on:
    The Statistical Interpretation of the Coefficient of Repeatability

    Bartlett et al. have reported on the clinical viability of the MPS 9000, a heterochromatic flicker photometry (HFP) device used to estimate macular pigment optical density (MPOD).[1] Coefficient of repeatability (CoR) values were used to determine the test-retest repeatability and reproducibility of the MPS 9000. While the observed CoR of 0.33 is indeed high, and, superficially at least, raises concern regarding the clin...

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    Conflict of Interest:
    None declared.
  • Published on:
    Author's response

    As a research group with no commercial interest in any macular pigment optical density (MPOD) measurement devices, or nutritional supplements, we feel that we were well-placed to carry out this independent clinical assessment of the reliability of MPS 9000. Our study was prompted by the fact that we could find no reported coefficient of repeatability value within the literature, and none was provided by the manufacturer...

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    Conflict of Interest:
    None declared.